Oil burning apparatus



April 13, 194-3. DONLEY 2,316,227

OIL BURNING APPARATUS Filed April 5, 1940 Patented Apr. 13, 1943 OILBURNING APPARATUS )4 Harold B. Donlcy, Columbus, Ohio, assignor toColumbus Metal Products,

Inc., Columbus,

Ohio, a corporation of Ohio 5 Claims.

This invention relates to oil burners and, more particularly, tohydrocarbon burners wherein a liquid fuel is admitted into the bottom ofa vessel having an open top and perforated air-admitting side walls,wherein the liquid oil introduced into the bottom of the vessel is,under the influence of heat, vaporized or gasified and admixed withlimited quantities of air to produce a hydroxylated fuel mixture and towhich mixture additional quantities of air are added to effect flamecombustion.

Oil burners of this type are frequently used in heating systemsrequiring two stages of combustion: the first stage is a low-fire orpilot stage and the second stage is known as the high-fire or normalcombustion stage. These stages are controlled by varying the amount ofvolumetric inflow of liquid oil into the bottom of a vaporizing vessel.Thus, when a demand for heat is created, a fuel flow regulating valve,disposed in an oil line leading to the burner, is opened to providemaximum oil flow and," after the heat demand has been satisfied, theregulating valve is closed, or partially closed, so that but arestricted flow of oil will be continuously delivered to the vaporizingvessel of the burner. Considerable difficulty has been encountered, inthe operation of burners of this character, in the matter of providingefiicient and well sustained low-fire combustion. A

burner vessel may operate effectively on highflre combustion but veryunsatisfactory under low-fire or pilot conditions;

I Accordingly, it is one of the primary objects of communicatingrelatively adjacent to the single bottom wall of the vessel and to whichbottom oil is delivered in quantities sufficient to ineet definitecombustion needs, the smaller of the vaporizing chambers having its.side walls formed with openings providing for the entrance of air inamounts adequate to maintain efficient pilot or low-fire conditions and,similarly, the walls of the larger chamber are likewise formed withair-admitting openings so placed in an adequate number to produceefficient maximum combustion requirements, both chambers having a com-A'pplication April 3, 1940, Serial No; 327,679

, thereof.

mon bottom to which oil is delivered by an associated fuel supplycontrolling means. i

For a further understanding of the invention, reference is to be had tothe following description and the accompanying drawing, in which similarcharacters of reference denotelike and corresponding parts throughoutthe several views In said drawing:

Fig. l is a top plan'view of an oil burner con- Fig.3 is a sectionalview through on oil flow regulating valve.

Referring more particularly to the drawing, my improved oil burnercomprises a vaporizing vessel having a concave bottom wall 5 and anupstanding vertical wall 6, the latter being formed at one side with anipple I, in which is threaded one end of an oil supply pipe 8.Connected with and arising from the wall 6 is a cylindrical shell 9, thelatter having spaced rows of air-admittin openings l0 formed therein.The interior of the shell 9 is in open communication with the bot tom ofthe vessel and forms a hydroxylating or high-fire fuel carburetingchamber H. Alsdcan ried by the bottom-forming member of the vessel is asecond cylindrical shell it, which is arranged adjacent to and inparallel order with the shell 9, the shell 12, however, beingconsiderably smaller in diameter than the shell 9. The shell I2 is inopen communication with the bottom of the vessel and is provided with aplurality of rows of air admitting openings I3, suflicient in numher andarrangement to cause the shell 12 to constitute a low-fire or pilotcombustion chamber M. The bottom of the shell l2 depends at one side toprovide a curved baille l2a, the latter terminating above the level ofthe liquid fuel pool normally maintained on the bottom wall 5.

Surrounding this multi-chambered vaporizing vessel is an outer casingIF, the side and bottom walls of the casing I 5 being spaced from thecomplemental walls of the vaporizing vessel to per,- mit of a free flowof air therebetween, the chamber I5 having connected therewith anair-supplying duct l6, through which air may be advanced either undernatural draft or forced flows The top wall ll of the casing I5 is joinedwith the upper annular edges of theconditions.

shells 9 and I2, the top walls I 1 also receiving throat rings 18 and Wewhich project over the open tops of the combustion chambers H and M,respectively.

In the operation of the burner, when it is desired to create andmaintain a maximum or peak combustion stage, known as the high-firestage, the required amount of liquid oil flows from the supply pipe 8and spreads in the form of a she]- low pool or film over the concavebottom wall of the vaporizing vessel. Due to heat developed by theoperation of the burner, this liquid oil is vaporized or gasified,passing upwardly into the mixing chamber ll. Air is drawn or forced intothe chamber II through the openings 10 in sufficient volumes to combineor unite with the oil vapors or gases to produce a rich hydroxylatedmixture which does not contain sufiicient oxygen to produce flamecombustion until additional quantities of oxygen are combined therewith.Such additional supplies of oxygen may be secured from the atmospherearound the top of the combustion chamber II or, in part, supplied by theupper rows of the openings 50, as is common in 'so-called hydroxylatingburners of this type. After the heat demand has been supplied, automaticdevices operate to reduce the quantity of oil delivered to thevaporizing vessel in order to establish low-stage or pilot combustion.Such restricted flow of oil results in the flow of the liquid oil overthe bottom wall 5 immediately beneath the open end of the chamber M andnot in such quantities as to spread out over the full area of the bottomwall 5.

Under such restricted flow of oil, the vapors produced therefrom arisefrom the bottom wall 5 and pass upwardly into the chamber M, where thevapors are first admixed with air drawn or forced into the chamber 14 bythe lower row or rows of the openings l3, forming a carburetted mixture,which is subsequently burned within the confines of the chamber l4 bysecondary supplies of air admitted through the upper rows of theopenings l3. Thus, in the design of the vaporizing vessel, a separatevaporizing chamber is produced for both high and low stages ofcombustion, the shape of the chambers and the number of air admittingopenings provided therein being proportioned or dimensioned to providethe best operating conditions for each stage. Many advantages accruefrom the use of this construction, among which may be mentioned theestablishment of steady, reliable low stage or pilot combustion, whichis exactly the same as that obtained in the high stage combustionconditions in efiecting the efiicient burning of oil and minimizingcarbon or smoke formation.

Any suitable apparatus may be used in association with the oil supplyline 8 for providing the high and low rates of oil flow to thevaporizing vessel. Such apparatus has been diagrammatically illustratedin Fig. 3, wherein the pipe line 8 has positioned therein a valve l9.The casing of this valve includes an internal divisional wall having arestricted port 2|, the eilective area of which may be adjusted by a setscrew 22. Under low fire conditions, oil flowing by the action ofgravity or positive pressure is advanced in a reestricted stream throughthe port 2| and thence delivered to the bottom wall 5 of the vaporizingvessel. To permit of maximum oil flow, the wall 20 is formed with atapered opening 23, adapted "to receive the correspondingly tapered endof a valve stem 24. Normally, the stem is maintained in a seatedposition within the opening 23 by the stem of a coil spring 25.Surrounding the upper end of the stem 24, is an electrically energizedcoil 26, which forms a part of a circuit 21 g in which a thermostat 28may be disposed. When the circuit 21 is closed by the action of thethermostat, the coil 26 is energized to efiect the elevation of the stem24 against the resistance of the spring 25, thus uncovering the opening23 and providing for a maximum of oil flow to the vaporizing vessel.

While a preferred embodiment of the improved oil burner has been setforth, nevertheless, it will be understood that the same is subject toconsiderable variation or modification without departing from the scopeof the invention as defined by the following claims.

What is claimed is:

1. An oil burner comprising a pan-like vessel, a plurality of unequaldiameter cylindrical shells arising from said vessel in spaced relation,said shells being provided with vertically and circumferentially spacedair admitting openings around the entire periphery, means for supplyingregulatable quantities of fuel to said vessel in registration with thesmaller diameter shell, and a casing surrounding said shells and spacedtherefrom to provide an air chamber extending completely around eachshell, communication between the interior of said shells and saidchamber being established by the openings in the side walls of saidshells.

2. An oil burner comprisinga pan-like vessel, a plurality of unequaldiameter cylindrical shells arising from said vessel in spaced relation,said shells being provided with vertically and circumferentially spacedair admitting openings around the entire periphery, a portion of theside wall of the smaller shell nearest the larger extending downwardinto said vessel and terminating in slightly spaced relation from thebottom thereof, means for supplying regulatable quantities of fuel tosaid vessel in registration with the smaller diameter shell, and acasing surrounding said shells and spaced therefrom to provide an airchamber extending completely around each shell, communication betweenthe interior of said shells and said chamber being established by theopenings in the side walls of said shells.

3. .An oilburner comprising a pan-like vessel, a plurality of unequaldiameter cylindrical shells arising from said vessel in spaced relation,said shells being provided with vertically and circumferentially spacedair admitting openings around the entire periphery, means for supplyingregulatable quantities of fuel to said vessel in registration .with thesmaller diameter shell, and a casing surrounding said shells and spacedtherefrom to provide an air chamber extending completely around eachshell, communication between the interior of said shells and saidchamber being es tablished by the openings in the side walls of saidshells, said casing having a top wall provided with openingscorresponding in size and register- I ing with the upper ends of saidshells, and throat rings positioned in the openingsin said top wall.

4. An oil burner comprising a pan-like vessel of oval contour whenviewed in plan, said oval having one large end, a cylindrical shellextending upward from each end of said vessel, said shells beingindependent of one another and having spaced air admitting openings inthe side walls, fuel conducting means communicating with the smaller endof said vessel, and a casing surrounding said vessel and shells andbeing spaced therefrom to provide an air chamber. air from said chamberbeing admitted into said shells through said openings.

5. In an oil burner, a vessel, means for supplying regulatablequantities of fuel to said vessel, a plurality of hollow shells arisingfrom said vessel in spaced independent relationship, one of said shellsbeing disposed adjacent to the fuel inlet, bailie means extending acrosssaid vessel between the shell adjacent to the oil inlet and an adjacentshell, air admitting openings formed in the side walls of said shells,and easing means surrounding said shells and spaced therefrom to providean air chamber, communication between said chember and the interior ofsaid shells being established through the openings in the walls of saidshells.

- HAROLD B. DONLEY.

